I need to install R 3.0.2 because a needed library isn't compatible with 3.0.3 yet (the latest).

I can install the older version of R like so:

sudo apt-get install r-base=3.0.2-1precise0

However all the dependencies of r-base try and install with 3.0.3

root@foo:~# apt-get install r-base=3.0.2-1precise0
Reading package lists... Done
Building dependency tree
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:
The following packages have unmet dependencies:
r-base : Depends: r-recommended (= 3.0.2-1precise0) but 3.0.3-1precise0 is to be installed
E: Unable to correct problems, you have held broken packages.